1. Field of the Invention
The present invention relates to bearing mountings, and more particularly, to a bearing mounting for a shaft in a gas turbine engine.
2. Description of the Prior Art
In order to avoid slippage or skidding of roller bearings, the rollers and an inner race can be inserted into an outer race or support which is slightly "out-of-round". Out-of-round means that the outer race is slightly oval with the minor axis of the race (determined by the inner raceway of the outer race) being less than the diameter of the circumference of a circle tangent to the outer surfaces of the assembled bearing rollers. When the assembled bearing rollers and inner race are pressed into the outer race, the inner raceway of the outer race will be forced to assume a circle, and thus a constant load is forced on the rollers, preventing slippage of the rollers. The outer race could also have curvilinear triangular configuration in its out-of-round shape. The out-of-round shape of the inner raceway may be obtained by first providing a right cylindrical race with a circular inner raceway and then machining the inner raceway to a curvilinear triangular shape.
Most conventional out-of-round race configurations are provided in bearing supports which are in the same radial plane as the bearing. The bearing supports are normally structurally connected to the engine casing in the case of a gas turbine engine. Thus, the preloading of the bearing by out-of-round configuration of the outer race can only be adjusted with difficulty in view of very limited tolerances which can be provided between the outer race and the remaining bearing support structure.